A wheel-guide rail named above emerges from DE 21 04 049 A. The towing device in that document for vehicles, especially for washing systems, has two guide rails between which the wheels of one side of the vehicle are moved. The guide rails have a flat web that is arranged essentially perpendicular to the floor of the car wash system and on whose upper end a longitudinal bar with a circular cross section is arranged.
FIGS. 1-3 show other wheel-guide rails for car wash systems according to the class. In FIG. 1, a left foot 1 of a not-shown gantry post of a movable washing gantry of a car wash system is shown that can be moved in a direction of travel F along a running rail 2 on the floor B of a washing system. On the foot 1 there is a wheel-rim washer 3 that is shown schematically and points in the direction of a wheel rim of a vehicle to be washed. In order to be able to drive the vehicle to be washed as centrally as possible with respect to the gantry posts 1, 1′ indicated in FIG. 2 by the feet in a travel range 4 of the car wash system, wheel-guide rails 5, 5′ offset toward the travel range 4 next to the running rails 2, 2′ are mounted on the floor of the car wash system. As emerges, in particular, from FIG. 2, the two wheel-guide rails 5 and 5′ define the travel range 4 between which the wheels of a vehicle to be washed should move.
FIG. 3 shows examples for cross sections of known wheel-guide rails. A wheel-guide rail 6 shown in FIG. 3a) consists of a rectangular steel hollow profile, wherein the edges are slightly rounded. In a floor 6a and an end face 6b of the wheel-guide rail 6, passage boreholes are formed at defined distances, wherein the wheel-guide rail 6 can be screwed on the floor B of the washing system through these boreholes. FIG. 3b) shows another known wheel-guide rail 7. There, the wheel-guide rail from FIG. 3a was welded onto a floor plate or ground beam 7c, so that no passage boreholes are necessary in an end face 7a and a floor 7a of the wheel-guide rail 7. The wheel-guide rail 7 is then fastened by screws of the floor plate or ground beam 7c on the floor B of the washing system. A known wheel-guide rail 8 shown in FIG. 3c) also has a floor plate or ground beam 8a for mounting on the floor B of the washing system, while the guide part of the wheel-guide rail 8 is produced from a steel tube with a circular-ring-shaped cross section.
The known wheel-guide rails 5, 5′ are used to guarantee that, while the vehicle is moving, the driver positions this vehicle as centrally as possible with respect to the lateral treatment devices, in order to have the most uniform travel path as possible in the case of treatment devices acting laterally on the vehicle. For example, the wheel washers 3 and 3′ shown in FIG. 2 can be moved from the position away from the illustrated vehicle into the extended position not shown in FIG. 2 for washing the wheel rims. In order to achieve a good washing result here, it is desirable to press both onto the wheel rims with approximately the same contact pressure, which is possible, above all, when the vehicle is positioned exactly centrally relative to the gantry posts 1, 1′. A position of the vehicle that is not centered could have the result that the travel paths or ranges of treatment assemblies are not sufficient and therefore inadequate cleaning of the vehicle is produced. In addition, the wheel-guide rails 5 and 5′ should guarantee that the vehicle is not in an area at risk of collision with the treatment assemblies or other parts of the washing gantry when the moveable washing gantry travels over the vehicle, for example, damage to the outside mirrors.
In order to guarantee this guide function, the wheel-guide rails 5, 5′ must be high enough that the driver of the entering vehicle notices possibly driving against or also over a wheel-guide rail 5, 5′, in order to be able to perform counter-steering. This is not a problem in the case of small, lightweight cars with small wheels, because contact with the typically 60 mm high wheel-guide rails 5, 5′ with rectangular cross sections is easily noticed. However, more and more there are large, heavy vehicles with large vehicle widths and large wheel or wheel-rim diameters, for example, 21″ wheel rims in the case of sports cars, off-road vehicles, or so-called SUV vehicles. In the case of these vehicles, driving against or over the wheel-guide rails 5, 5′ is often not noticed by the driver due to the tire size and the large vehicle weight, so that the vehicles often come to lie off-center in the travel range 4 or even on the wheel-guide rails 5, 5′. Here, when the washing gantry moves over the vehicle, projecting vehicle parts, for example, outside mirrors, on the side of the vehicle in question are often damaged. In addition, the cleaning result is made worse, because the vehicle is too far from the treatment assemblies on the other side of the vehicle. Such large vehicles often have a large track width and thus outside wheel spacings, so that, in the case of old or narrow car wash systems, the wheel-guide rails are too close to each other and are always driven against or over.
In the case of such large vehicles, in order to be able to detect contact with the wheel-guide rails 5, 5′, in a first approach, the height of the wheel-guide rails could be increased. This has the disadvantage, however, that in the case of vehicles with small tires or low-cross-section tires, not only the rubber tires, but also the wheel rims contact the wheel-guide rails 5, 5′ that are typically made from steel, and in this way are damaged. Especially for the large vehicles named above, due to the large wheel-rim diameter, low-cross-section tires are often used, so that, in connection with the large vehicle width, such vehicles already contact the wheel-guide rails disproportionately often with their usually expensive wheel rims. Damaging such expensive wheel rims is very disadvantageous for the operator of the car wash system due to the high indemnity payments. These cases would be increased by the higher wheel-guide rails.
To avoid this disadvantage, above all, for low-cross-section tires, a second solution would be for the wheel-guide rails to have a lower construction. This has the result, however, that driving against or over the wheel-guide rails is no longer noticed due to these large vehicles, so that a good cleaning result is not achieved and there is also the risk of damage to other vehicle parts or treatment assemblies of the washing system.
A car wash system disclosed in U.S. Pat. No. 3,596,241 has wheel-guide rails made from tubes with switch arms arranged on these rails for detecting the vehicle tires. The switch arms are here mounted rigidly on the outside of the tube away from the vehicle and extend through round openings into the tubes on the side close to the vehicle. Both the tubes and also the switch arms are made from electrically conductive material and are connected to a switch display. In the normal state, the switch arms do not contact the tubes and also do not extend into the specified travel range of the vehicle. If the vehicle moves outside of the travel range, a wheel of the vehicle deforms one of the switch arms that then contacts its opening. In this way, an electrical circuit is made and a corresponding signal is displayed on a display. This construction has the disadvantage that the switch arms necessarily project outward and into the travel range due to their function. This raises the risk of unintentional triggering, for example, due to objects in the travel range that deform the switch arms or due to short-circuiting of the open contact (tubes and switch arms) of the switch circuit. This also raises the risk of damage to the switch arms due to vehicles driving against or over these arms. In addition, for the operator or the user of the system, there is the risk of electrical shock due to the open contacts. Also, a measurement of the distance is not possible, because the switch arms merely cause the signal to be turned on or off. The switch arms allow only the detection of whether a vehicle is too close to the wheel-guide rail at some point of the wheel-guide rails, because the activation of a switch arm triggers the display signal, so determining a special switch arm from several triggered switch arms is not possible.